A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
The present invention relates to devices designed to provide for controlled environments wherein personnel would be required to have access to, and periodically be required to work in these controlled environments. Many types of environments which provide for control of parameters such as temperature, humidity and the like may be fitted with the invention, but the primary application for the device is in utilization with environments such as walk-in coolers and freezers.
Specifically, the present invention relates to a device which incorporates both a switch means such as a magnetic contact mounted on the compartment door and door frame to sense status of the door being opened or closed, and a manually operated push button switch located inside of the compartment with functional integration between the two switches as sensors for the operation of the invention. Opening or closing of the compartment door or activation of the push button will cause the device to perform its intended functions, which include interruption and restoration of normal operation of systems and components that are in place to provide creation of the desired environment such as a refrigeration system, control of interior lighting which is provided for illumination of the compartment when personnel are inside and control of an audible, visual and remote notification annunciation system to indicate conditions such as the door being left ajar or operational conditions where annunciation to the user of pending or other functions of the device is desired.
Principles of operation of refrigeration systems for walk-in coolers and freezers and the physical designs of these compartments are fairly standardized and well documented. An inherent component of walk-in coolers and freezers is the door and the doorway which provides access to the interior of the compartment. Obviously, this door and doorway are utilized by personnel as a means of entering and exiting the compartment to perform various tasks such as retrieving or returning perishables, stocking, cleaning, doing inventory and the like. While necessary for utilization of the compartment, opening of the door can have detrimental effects on overall system tags performance and can also have impact on perishable items that are contained within the walk-in. Whenever the door is opened, cold inside air is exchanged with warmer outside air, resulting in a substantial expenditure of energy needed in attempting to maintain compartment temperature as the system will constantly be calling for refrigeration to compensate for the door opened condition. This is particularly the case when the door is to be opened for a prolonged period of time such as when a compartment is being stocked with product. The thermal exchange of air that takes place also causes air outside of the compartment to drop in temperature which can be undesirable as well. In severe cases when a door is left open for too long a period of time or if a door is accidentally left ajar, this can cause damage to or spoilage of the product that is contained in the compartment.
Another matter of concern with walk-in coolers and freezers is exposure of personnel to the environment created by the operating refrigeration system. Attempting to perform any of the aforementioned operational or maintenance tasks with the refrigeration system running exposes personnel to abnormally cold temperatures, particularly in walk-in freezers. This condition becomes more dramatic when personnel have work to do inside of a compartment for a prolonged period of time and have elected to work with the door closed so as to minimize thermal exchange. In these instances, temperatures can become extremely uncomfortable and even life threatening.
Another component that is integral to virtually all walk-in coolers and freezers is illumination means for the interior of the compartment. These illumination means are typically controlled by a light switch adjacent to the door of the compartment. Operation of the light switch is personnel dependent with the result being that lights are often left on unnecessarily when the door is closed. While this does not adversely affect performance of the compartment or compromise product integrity, it nevertheless causes an unnecessary waste of energy and thus increases operating expenses.
There are numerous devices and techniques known in the field which, independently or in combination, attempt to address these situations. For example, regarding refrigeration functions, there are various timing devices, both mechanical and electronic, which can be used to disable operation of the fans and solenoid valve so as to temporarily interrupt operation of the refrigeration system. These devices are typically manually activated and will interrupt operation for a selected period of time after which the refrigeration system will automatically restart. While these devices are effective for their intended purpose they are limited in that they only respond to their internal timing mechanisms and have no connection with functional operation of the box such as whether the door is opened or closed. They will only turn refrigeration back on when they have xe2x80x9ctimed outxe2x80x9d, even if the task for which they have been activated has been completed and ideally, the refrigeration system should have restarted.
Another approach often used is to mount a switch on the door frame which deactivates the fans and solenoid valve when the door is opened and reactivates them when the door is closed. However, this method has a number of disadvantages. Firstly, turning components on and off every time the door is opened or closed can cause excessive wear to the solenoid valve, the fans and the compressor. This is particularly true of food service facilities, where doors can be opened and closed frequently, especially at busy times of the day when personnel are entering and exiting the compartment to retrieve and return perishable items. Secondly, this approach does not provide a means for working inside of the compartment with the refrigeration off when the door is closed. Thirdly, this approach can result in catastrophic product loss if a door is left even slightly ajar as the refrigeration system in this scenario would not turn back on. All of these represent significant shortcomings to utilizing this method.
There are also manually operated techniques that are utilized such as switches that will allow personnel to shut off the fans and solenoid valve so as to temporarily de-activate the refrigeration system when so desired. However, these methods rely on human responses for proper operation and thus suffer from the same flaws as those that are apparent with light switches. If personnel fail to re-activate the refrigeration system the results can be disastrous with substantial loss of perishable items.
Regarding audible, visual and remote notification capable annunciation systems there are well known approaches and techniques which exist in the prior art that sense the status of the door and provide a door ajar alarm if the door is opened for too long. Some of these devices even incorporate a timed relay function to provide some interruption and restoration capability of the operation of the refrigeration system in response to the door being opened or closed. However, because of the limited capabilities of devices which are only a door ajar alarm or even in devices which offer some interruption and restoration capabilities, the annunciation system functions only as a door ajar alarm and it is not designed or intended to annunciate any other pending functions of the device. Also, none of these devices offers a means for activation other than sensing the status of the door, so functionality is limited. Additionally, none of the aforementioned devices provides automatic control of interior illumination means.
It is, therefore, desirable to create an apparatus that provides a method and a means for addressing these shortcomings by firstly, combining refrigeration system interruption and restoration functions, control of illumination means functions, and audible, visual and remote notification functions into an appropriately configured and functionally integrated device, and secondly, providing a dual input sensor means that both senses the status of the door and also provides manual user activation capability with functional integration of operation between these two sensors as a means for accessing device functions.
Accordingly, it is an object of the present invention to provide a means for interruption and restoration of operation of a refrigeration or environmental system.
It is another object of this invention to provide a means for integrating status of the compartment door being opened or closed with interruption and restoration of operation of the refrigeration system.
It is another object of this invention to provide a means for manually interrupting operation of a refrigeration system.
It is another object of this invention to provide a two input sensing means in the form of a switch such as a magnetic contact to monitor the status of the door and a switch such as a push button mounted inside of the compartment to provide manual activation with functional integration between the two switches as a means for interruption and restoration of operation of a refrigeration or environmental system.
It is another object of this invention to provide a user adjustable means for delaying interruption of operation of a refrigeration system for a selected period of time relative to when the compartment door is first opened.
It is another object of this invention to provide a means for control of illumination means for the interior of a refrigerated or environmental room.
It is another object of this invention to provide a means for integrating status of the compartment door being opened or closed with control of illumination means for the interior of a refrigerated or environmental room.
It is another object of this invention to provide a means for manual activation of illumination means for the interior of a refrigerated or environmental room.
It is another object of this invention to provide a two input sensing means in the form of a switch such as a magnetic contact to monitor the status of the door and a switch such as a push button mounted inside of the compartment for manual activation with functional integration between the two switches as a means for control of illumination means for the interior of a refrigerated or environmental room.
It is another object of this invention to provide a means for annunciating a door ajar alarm condition or other function of the device.
It is another object of this invention to provide an audible and a visual alarm as well as an alarm relay for remote notification purposes as a means for annunciating either a door ajar alarm condition or other function of the device.
It is another object of this invention to provide a user adjustable means for delaying activation of the audible alarm for a selected period of time relative to when the door is first opened.
It is another object of this invention to provide a means for automatically restoring operation of a refrigeration system in a door ajar alarm condition.
It is another object of this invention to provide a means for sequentially integrating audible door ajar alarm annunciation with automatic restoration of operation of a refrigeration system.
All of the above objectives are incorporated into the invention and will function in a manner as determined by the software and/or circuit design and in accordance with settings of user adjusted parameters as described in the detailed description of the preferred embodiments.
The present invention is an apparatus for monitoring, indicating and controlling conditions of a refrigeration system having a refrigerated compartment, a door for accessing the refrigerated compartment, an interior light source for illuminating the interior of the compartment and a fan and coolant valve arrangement for refrigerating the compartment comprising. The apparatus generally includes a door switch for detecting an open or closed condition of the door to the refrigerated compartment, a light relay for providing power to the interior light source of the compartment in an activated state and for terminating power to the light source in a deactivated state and a microprocessor electrically connected with the door switch and the light relay for activating the light relay when the door switch detects a door open condition. The microprocessor further includes an interior light timing algorithm for deactivating the light relay after a predetermined delay when the door switch detects a door closed condition.
Preferably, the apparatus further includes an audible alarm electrically connected to the microprocessor and the microprocessor further includes a manually adjustable alarm timing algorithm for activating the audible alarm after a predetermined delay when the door switch detects a door open position.
Preferably, the apparatus further includes a visual alarm electrically connected to the microprocessor that is activated by the microprocessor when the door switch detects a door open position.
In alternate embodiments of the present invention, the apparatus further includes a fan relay electrically connected to the microprocessor for providing power to the fan of the refrigeration system in a deactivated state and for terminating power to the fan in an activated state and a valve relay electrically connected to the microprocessor for providing power to the coolant valve of the refrigeration system in a deactivated state and for terminating power to the coolant valve in an activated state. Activation of the fan relay and the valve relay can be controlled by a user selectable switch. When the switch is in a first position, the microprocessor activates the fan relay and the valve relay when the door switch detects a door open position. When the switch is in a second position, the microprocessor activates only the fan relay when the door switch detects a door open position. In this embodiment, the microprocessor may include a manually adjustable refrigeration timing algorithm for activating the fan relay and the valve relay after a predetermined delay when the door switch detects a door open position and for deactivating the fan relay and the valve relay after a predetermined delay. The refrigeration timing algorithm can also be programmed to deactivate the fan relay and the valve relay after a predetermined delay after the audible alarm is activated.
In another embodiment, the apparatus includes a manually depressible push button electrically connected to the microprocessor. The push button is located within the refrigerated compartment for manually activating various device functions. If the audible alarm has been activated due to a door open condition, the push button can be made to deactivate the audible alarm and reset the alarm timing algorithm when depressed. If refrigeration operation has been restored as a result of a door ajar alarm occurring, the push button may further perform the function of activating the fan relay and the valve relay to terminate refrigeration operation when depressed. If the door is closed, the push button, when momentarily pressed, will cause the light relay to activate or remain activated so that the interior of the refrigerated compartment will remain illuminated, and will also perform the function of activating the fan relay and the valve relay to terminate refrigeration operation. Additionally, the push button, when momentarily pressed, will reset certain alarm algorithms which may occur when the door is closed. If depressed for a predetermined period of time when the door is closed, the push button provides immediate activation of certain alarm algorithms contained within the microprocessor. These include activation of all alarm annunciators, activation of the light relay so that the interior of the compartment will remain illuminated, and activation of the fan relay and the valve relay to terminate refrigeration operation.
Preferably, the push button is accompanied by a secondary audible annunciator such as a piezo type horn that is connected to and is activated by the microprocessor. The purpose of this horn is to provide audible notification inside of the compartment of pending functions of the device that require a response to personnel who may be contained therein.
Thus, the present invention provides a self-contained and functionally integrated apparatus which provides interruption and restoration capabilities of operation of a refrigeration or environmental system, control of interior illumination means, an audible and visual annunciation system to annunciate a door ajar condition or a pending or other function of the device and a dual input sensing means consisting of magnetic contacts to monitor the door status and a push button switch to be mounted inside of the compartment with operational integration between the two input switches so that all possible modalities of operation for the compartment are addressed as a means for operating and controlling the apparatus.
For a better understanding of the present invention, reference is made to the following detailed description to be taken in conjunction with the accompanying drawings and its scope will be defined in the appended claims.